Refrigerating lettuce and the like



y 9- w. w. DODGE J REFRIGERATING LETTUCE AND THE LIKE Original Fil ed Jan. 21,1957

FIE I l4 es/ey 55??? AT ORNE Reiaued July 11, 1939 UNITED STATES 'PATE NT OFFICE REFRIGERATING LETTUCE AND THE LIKE Wesley W. Dodge,

Paterson Pacific of California Oakland, Parchment Calil, assignor to 00., a corporation Original No. 2,124,412, dated July 19, 1938, Serial No. 121,574, January 21, 1937. Application for reissue March 6 Claims.

This invention perishable commodities, fruit, vegetables and the Lettuce and that subsequently they can With lettuce, diseases of the field aswell as effects occasioned by the elements are factors affecting" quality. The most common of the field diseases is that known as tip burn, but bruising, frost injury, worm injury and wind hum also serve to depreciate the lettuce quality. Depending upon the time of the year, the lettuce is s'uir- 3 ing of an entire carloacl of lettuce three hundred crates of lettuce. Rapid handling is therefore the practice. Since the labor employed does not distinguish between haste and speed, the lettuce suffers by being roughly handied and bruised. Many bruises do not appear on 27, 1939, Serial No. 264,473

cracking. open.

With lettuce packed as in the Gallagher and Grande patents, even though the butts of the lettuce are up, the lettuce becomes waterdogged. The undesirability of this is apparent when .it is That is, the ribs chased by a retailer,

and put on display.

extent nor nearly as readily; furthermore, lettuce packed in accordance with the present invention is substantially free 01' rib cracking, while the lettuce will freshen up very materially when placed upon a retailer's shelf and sprinkled with water.

I have found that while all with the lettuce should not should be possible to moisture contact be eliminated, it

Thus, a is imand I have found packed cased heads of lettuce a phere. 7

At this point cold but humid atmosit is possibly well to point out suitable paper can be Q jsiprovide an improved tact with the lettuce of packing head is not, of course, limited to lettuce,

are substantially waterproof, and .materials which are waterproof and yet permeable to water in the form of vapor or moisture. This distinction is not new with me, so far as the distinction is concerned, but is an important one insofar as the present invention is concerned. The wrappers which I employ maintain their integrity in the presence of moisture and do not permit water to pass as such. While they are slightly pervious to moisture, they obstruct water passage. In effect, therefore, my wrappers are waterproof but not moistureproof.

As suitable shielding materials I have found I can use any wrapping material which is substantially waterproof and which will nevertheless permit moisture to pass to an extent sufllcient to maintain within it, when used as a wrapper, a humid atmosphere. As particular materials, I have successfully used those produced by the Paterson Parchment Paper Company and known to the trade as Patapar and Durapa These materials are sometimes characterized as vegetable parchments. Of course, any other used, as can any wrapping material which is substantially waterproof and which is nevertheless permeable to moisture or arranged so that moisture can pass to the lettuce. The paper or wrapper should be tough; at least its strength should not disappear when it is soaking wet.

The present invention enables the shipper of lettuce to use ice that comes directly from the ice manufacturing plant or ice storage without leaving it standing to warm up or thaw ou The majority of lettuce shippers are not aware of the fact that commonly ice is colder than 32,and, being unaware of this, place the ice in direct conimmediately after receiving the ice, thereby causing the outer leaves of the head to show freezing injury.

Ice is frequently delivered at temperatures ranging from 15 to 20 F., with an average delivery temperature at the packing house of about 24 F. This low temperature is detrimental to the lettuce if placed in direct contact therewith. Therefore, in accordance with the present invention, the lettuce shield checks the cold sufficiently and for a period that is long enough to up whereby the "lettuce does not show freezing injury. As the ice melts, the water follows the shield or wrapper no time does the super-cold ice or cold .ice water touch the bulk of the lettuce under this invention. Under the method practiced today, as the cold ice melts the lettuce absorbs the water and the super-cold ice is always next to the lettuce. This results in the outer leaves of the lettuce freezing, resulting in an early decay in transit.

It is in general the broad object of the present invention to provide a new and improved method lettuce for shipment to market. The invention although it is particularly applicable to this commodity. Many fresh fruits and vegetables can be advantageously handled according to the present invention.

Another object of the present invention is to provide a packing for lettuce such that the lettuce does not become waterlogged.

- Another ,object of the present invention is to packing for certain vegetawithout the crate.

' tuce is then and at I 21,144 bles enabling the vegetables to be delivered to the market in a comparatively fresh condition so that they are easily revivi I ed and freshened.

The invention includes other advantageous features and objects, some of which, together with the foregoing, will appear hereinafter, wherein the present preferred manner of practicing the invention is disclosed.

In the drawing accompanying and forming a part hereof,

Figure l is a longitudinal cross-section taken through a freight car and illustrating a refrigerated pack embodying this invention.

Figures 2, 3 and 4 lettuce as practiced in accordance with this invention.

Figure 5 iso. perspective view of a lettuce pack.

Figure 6 is a cross-section on the line 6-6 of Figure 1.

Numeral 6 designates a suitable lettuce crate. In this crate are packed the various tiers of lettuce. Each tier can include a certain number of lettuce heads, either 16, 20 or 25 heads, depending 'upon the size of the lettuce. Each tier of the heads is shielded by a suitable wrapper i. This wrapper is made of any of the materials which I have previously discussed. I have used with success the "Durapak or Patapar papers previously mentioned, although other wrappers can be used. providingthey are substantially waterproof and are either inherently permeable to of the water int-o the packageis prevented; thus in Figure 51 have shown one end 8 overlapping the other end 9 for a considerable distance on the upper side Ill of thepack. It is also to be noted. that the end sections are tucked over as at E5. Instead of using a sheet, a sack or bag can be used, but I consider a sheet satisfactory.

The shielding of the lettuce can either be performed by hand or by machine,'and within or I prefer to position the paper and thenplace the lettuce thereon, folding the paper and tucking in the ends. The packed letplaced in the crate. A layer of ice, indicated as i I, is then placed upon the wrapped package. This operation is repeated, the wrapped layers and alternate ice layers being repeated until the crate is full, usually three tiers suiiicing to a crate.

plied should be'sufncient to compress the heads together without injury. I have used a pressure of Eve pounds per square inch, but this can be varied.

Since the wrapper is tough, the pressure of the ice does not break the wrapper, while the ice is securely pressed against all portions of the lettuce tier, ensuring that the lettuce is virtually encased in a top-sheet of ice. This operation is repeated -for each of the alternate layers of lettuce and ice, or else performed upon the crate asa whole after it has been packed. I prefer to press each layer of ice and lettuce so that adequate contact is secured as the crate is packed. This compessing of the ice and lettuce also enables much more ice to be worked into a crate, so that in the more temperate periods of the year it is not necessary to ice the refrigerator car employed as the vehicle in the transcontinental transportation of the products. Finally, the cover 22 is placed on the pack, the cover compressing the pack in the crate and securing it snugly in place. The top bows when sprung intoposition to provide a constant pressure upon the pack within the crate.

This pressure is uniformly distributed over all the heads in the crate, and is therefore not harmful. Instead, it provides an adequate contact between the ice and the wrapped heads, ensuring that refrigeration is maintained so long as the of refrigerator cars that the shippers of lettuce have lost sight of the fact that lettuce has a decomposition heat" or a respiration heat; that is, the lettuce is constantly giving on heat due to the life processes still going on within it. This is particularly so with lettuce that is over mature. If a localized high temperature is permissible and can occur in some portions of the refrigerator car, of course this process goes on much more rapidly, since it is one which increasing temperature assists. By providing the lettuce pack of my invention with an adequate ice supply in each crate or available for each crate, and by shielding the lettuce in the moisture permeable wrapper so that moisture passes to the icttuce therein, I have found that this matter of localized high temperature can be adequately cared for.

In the case of lettuce crates containing ice between each layer of shielded heads, the localized temperature problem is adequately cared for by the shielding action of the interposed waterproof material. The packed crates are merely covered with a layer 25 of top ice, ii climatic conditions make this desirable. Top icing is well known in the art and requires no explanation here, except to say it includes the spraying of ice particles in an air stream over the packed commodities. it is described in a catalog issued by Wesco Machinery Manufacturing Company and in the Philipps Patent No. 2,113,493 of April 5, 193a, and in the Brady Patent No. 2,123,878 of July 19,

The present invention enables dry packed lettuce to be shipped with adequate refrigeration but without the disadvantages of present practices. In this instance, the crates are placed on their sides (Figure l) with car strips 26 positioning the crate. Since the crates are lying on their sides, cold water from the melting top ice layer 24 will flow down over each crate. The wrappers or shields act as wicks to draw the cold water down between each layer of lettuce. This ensures adequate refrigeration and moisture control without danger of water logging the lettuce.

When only short distances are to be traversed, or when the atmospheric conditions are suitable,

ice need not be used, and the lettuce can be shipped under wholly dry conditions. In this instance, the pack of the present invention is of advantage since it seals in the CO: gas given off by the lettuce, whether the pack is dry or wet, thus preserving the lettuce by at least decreasing the rate of decomposition as well as retarding bacterial action. Since the top keeps the lettuce compressed, a substantially-fluid and gasv tight package is provided. The materials previously mentioned adequately supply the characteristics required for this end.

I claim:

1. A method of packing a product for shipment, said method comprising enclosing said product in a flexible, tough, waterproof, moisture permeable material having the capacity of resisting prolonged contact with water without disintegration, arranging such wrapped product in a container, contacting the so wrapped product with a quantity of ice fragments, and confining the ice so as to cause the meltage therefrom to flow over said wrapped product.

2. A shipping package comprising a container, a parcel arranged therein, a quantity of crushed ice distributed in said container in contact with said parcel and maintained by the container in contact with said parcel, said parcel comprising foodstufi wrapped with a tough, flexible, waterproof, moisture permeable wrapper having the capacity of resisting prolonged contact with water without disintegration. i

3. A shipping package comprising a crate, a. parcel arranged therein, a quantity of crushed. ice distributed in said crate in contact with said parcel, and means ior maintaining the parcel in contact with said ice, said parcel comprising foodstuff wrapped with vegetable parchment.

i. A shipping package for a vegetable product comprising a crate, layers of said product arranged said crate, a quantity of ice distributed between the layers, and a shield of a flexible, tough, substantially waterproof and moisture permeable matcriaiarranged in said. crate between. the ice and adjacent faces of said layers of said. product to maintain said ice and meltage there from out of contact with said product. i

5. The method of packing a vegetable product ior refrigerated shipment, comprising: interdistributing a quantity or" said vegetable product with a quantity of ooinminuted ice in a shipping container, and protecting said vegetable'product from wetting by meltage. from said ice, by interposing, during said interdistribution of ice and vegetable. product, a shield or" flexible, tough, subuct within said container and distributed therein in heat-transferring relationship with said ice, and a flexible, tough sheet of a substantially waterproof, moisture-permeable material interposed between said distributed ice and vegetable product substantially shielding said vegetable product from wetting by ice meltage yet permitting heat and limited moisture-transfer therebetween.

WESLEY W. DODGE.

-DIVSCLAEMER Re. No. 21,144.Wesley W. Dodge, Oakland, Calif. REFRIGERATING LETTUCE' AND THE LIKE. Patent dated July 11, 1939. Disclaimer filed September 6, 1943, by theassignee, Paterson Pacific Parchment 00.; the inventor approving, Hereby enters this disclaimer to claims 4, 5, and 6 in said patent.

[Qfiieial Gazette October 12, 1943.] v 

